Since the mid-1980s, asthma rates in the U.S. have skyrocketed to epidemic levels, particularly in young children. In the U.S. alone, around 16 million people suffer from asthma. Asthma is a serious chronic disorder, and in some cases life-threatening disease, of the lungs characterized by recurrent attacks of bronchial constriction, which cause breathlessness, wheezing, and coughing. Researchers have found that pesticide exposure can induce a poisoning effect linked to asthma.

Low-income populations, people of color, and children living in inner cities experience disproportionately high morbidity and mortality due to asthma. According to the National Institutes of Health’s National Institute of Allergy and Infectious Disease, African Americans are four to six times more likely than whites to die from asthma. Therefore, any time our policies allow regulators to permit uses of pesticides with known asthma effects, which is done daily, a disproportionate impact is felt in the African-American community. Among other policies, this toxics policy contributes to a cycle of poverty, as asthma is the leading cause of school absenteeism due to chronic illness. Learn more about pesticides and asthma.

Exposure to pesticides and the associated human health effects.Pesticides are used widely to control weeds and insect infestation in agricultural fields and various pests and disease carriers (e.g., mosquitoes, ticks, rats, and mice) in houses, offices, malls, and streets. As the modes of action for pesticides are not species-specific, concerns have been raised about environmental risks associated with their exposure through various routes (e.g., residues in food and drinking water). Although such hazards range from short-term (e.g., skin and eye irritation, headaches, dizziness, and nausea) to chronic impacts (e.g., cancer, asthma, and diabetes), their risks are difficult to elucidate due to the involvement of various factors (e.g., period and level of exposure, type of pesticide (regarding toxicity and persistence), and the environmental characteristics of the affected areas). There are no groups in the human population that are completely unexposed to pesticides while most diseases are multi-causal to add considerable complexity to public health assessments. Hence, development of eco-friendly pesticide alternatives (e.g., EcoSMART) and Integrated Pest Management (IPM) techniques is desirable to reduce the impacts of pesticides. This paper was hence organized to present a comprehensive review on pesticides with respect to their types, environmental distribution, routes of exposure, and health impacts.[Kim KH, Kabir E, Jahan SA. 2017. Sci Total Environ. 575:525-535.]

Occupational exposure to pesticides are associated with fixed airflow obstruction in middle-age.Population-based studies have found evidence of a relationship between occupational exposures and Chronic Obstructive Pulmonary Disease (COPD), but these studies are limited by the use of prebronchodilator spirometry. Establishing this link using postbronchodilator is critical, because occupational exposures are a modifiable risk factor for COPD.This study investigated the associations between occupational exposures and fixed airflow obstruction using postbronchodilator spirometry. One thousand three hundred and thirty-five participants were included from 2002 to 2008 follow-up of the Tasmanian Longitudinal Health Study (TAHS). Spirometry was performed and lifetime work history calendars were used to collect occupational history. ALOHA plus Job Exposure Matrix was used to assign occupational exposure, and defined as ever exposed and cumulative exposure unit (EU)-years. Fixed airflow obstruction was defined by postbronchodilator FEV1/FVC <0.7 and the lower limit of normal (LLN). Ever exposure to biological dust (relative risk (RR)=1.58, 95% CI 1.01 to 2.48), pesticides (RR=1.74,95% CI 1.00 to 3.07) and herbicides (RR=2.09,95% CI 1.18 to 3.70) were associated with fixed airflow obstruction. Cumulative EU-years to all pesticides (RR=1.11,95% CI 1.00 to 1.25) and herbicides (RR=1.15,95% CI 1.00 to 1.32) were also associated with fixed airflow obstruction. In addition, all pesticides exposure was consistently associated with chronic bronchitis and symptoms that are consistent with airflow obstruction. Pesticides and herbicides exposures were associated with fixed airflow obstruction and chronic bronchitis. Biological dust exposure was also associated with fixed airflow obstruction in non-asthmatics. Minimising occupational exposure to these agents may help to reduce the burden of COPD.[Alif SM, Dharmage SC, Benke G, Dennekamp M, et al. 2017. Thorax. pii: thoraxjnl-2016-209665]

Environmental pollutants and child health-A review of recent concernsIn recent years, many new studies have evaluated associations between environmental pollutants and child health. This review aims to provide a broad summary of this literature, comparing the state of epidemiological evidence for the effects of a wide range of environmental contaminants (air pollutants, heavy metals, organochlorine compounds, perfluoroalkyl substances, polybrominated diphenyl ethers, pesticides, phthalates and bisphenol A) on child health outcomes. The review addresses effects on foetal growth and prematurity, neurodevelopment, respiratory and immune health, and childhood growth and obesity. Findings of recent prospective studies and meta-analyses have corroborated previous good evidence, often at lower exposure levels, for effects on foetal growth of air pollution and polychlorinated biphenyls (PCBs), for neurotoxic effects of lead, methylmercury, PCBs and organophosphate pesticides, and for respiratory health effects of air pollution. Moderate evidence has emerged for a potential role of environmental pollutants in attention deficit hyperactivity disorder and autism (lead, PCBs, air pollution), respiratory and immune health (dichlorodiphenyldichloroethylene - DDE - and PCBs), and obesity (DDE). In addition, there is now moderate evidence that certain chemicals of relatively recent concern may be associated with adverse child health outcomes, specifically perfluorooctanoate and foetal growth, and polybrominated diphenyl ethers and neurodevelopment. For other chemicals of recent concern, such as phthalates and bisphenol A, the literature is characterised by large inconsistencies preventing strong conclusions. In conclusion, since most of the recent literature evaluates common exposures in the general population, and not particularly high exposure situations, this accumulating body of evidence suggests that the unborn and young child require more protection than is currently provided. Large, coordinated research efforts are needed to improve understanding of long-term effects of complex chemical mixtures.[Vrijheid M, Casas M, Gascon M, Valvi D, Nieuwenhuijsen M. 2016. Int J Hyg Environ Health. 219(4-5):331-42]

Early-life exposure to organophosphate pesticides and pediatric respiratory symptoms in the CHAMACOS cohort.Authors investigated the relationship between early-life exposure to OPs and respiratory outcomes.Participants included 359 mothers and children from the CHAMACOS birth cohort. Dialkyl phosphate (DAP) metabolites of OP pesticides, specifically diethyl (DE) and dimethyl (DM) phosphate metabolites, were measured in urine from mothers twice during pregnancy (mean = 13 and 26 weeks gestation) and from children five times during childhood (0.5-5 years). Mothers reported their child's respiratory symptoms at 5 and 7 years of age. Higher prenatal DAP concentrations, particularly DE, were nonsignificantly associated with respiratory symptoms in the previous 12 months at 5 or 7 years of age. This association was strongest with total DAP and DE from the second half of pregnancy. Childhood DAP, DE, and DM concentrations were associated with respiratory symptoms and exercise-induced coughing in the previous 12 months at 5 or 7 years of age. Early-life exposure to OP pesticides was associated with respiratory symptoms consistent with possible asthma in childhood.[Raanan R, Harley KG, Balmes JR, et al. 2015. Environ Health Perspect. 123(2):179-85.]

Exacerbation of symptoms in agricultural pesticide applicators with asthma.Study investigated whether exacerbation of symptoms is associated with farming exposures among agricultural pesticide applicators with asthma.Participants were pesticide applicators with active asthma (wheezing and breathing problems in past 12 months) who completed enrollment questionnaires for the Agricultural Health Study (AHS). Exacerbation of asthma was defined as having visited a hospital emergency room or doctor for an episode of wheezing or whistling in the past 12 months. Exposures of interest were using 36 specific pesticides in the past 12 months and conducting various agricultural activities.The 926 AHS adult pesticide applicators with active asthma included 202 (22%) with exacerbation. Inverse associations with exacerbation were observed for two herbicides [glyphosate and paraquat] and several agricultural activities (repairing engines, grinding metal, driving diesel tractors, and performing veterinary procedures). Only asthma cases with allergies (i.e., doctor-diagnosed hay fever or eczema, 46%) had positive exacerbation-pesticide associations, with OR = 2.1 for the herbicide pendimethalin and OR = 10.2 for the insecticide aldicarb.The inverse associations with two pesticides and specific farm activities are consistent with the possibility that asthma cases prone to exacerbation may avoid exposures that trigger symptoms. Although limited by small sample size and a cross-sectional design, our study suggests that use of specific pesticides may contribute to exacerbation of asthma among individuals with allergies.[Henneberger PK, Liang X, London SJ, et al.2014. Int Arch Occup Environ Health. 87(4):423-32.]

Levels and sources of volatile organic compounds in homes of children with asthma.This study characterizes VOC levels in 126 homes of children with asthma in Detroit, Michigan, USA. The total target VOC concentration ranged from 14 to 2274 μg/m(3); 56 VOCs were quantified; and d-limonene, toluene, p, m-xylene, and ethyl acetate had the highest concentrations. Based on the potential for adverse health effects, priority VOCs included naphthalene, benzene, 1,4-dichlorobenzene, isopropylbenzene, ethylbenzene, styrene, chloroform, 1,2-dichloroethane, tetrachloroethene, and trichloroethylene. Concentrations varied mostly due to between-residence and seasonal variation. Identified emission sources included cigarette smoking, solvent-related emissions, renovations, household products, and pesticides. The effect of nearby traffic on indoor VOC levels was not distinguished. While concentrations in the Detroit homes were lower than levels found in other North American studies, many homes had elevated VOC levels, including compounds that are known health hazards. Thus, the identification and control of VOC sources are important and prudent, especially for vulnerable individuals. The most important sources included cigarette smoking, vehicle-related emissions, building renovation, solvents, household products, and pesticides.[Chin JY, Godwin C, Parker E, et al. 2014. Indoor Air. 24(4):403-15.]

Pesticides and Asthma: Challenges for EpidemiologyAssociations between pesticide exposure and asthma in children, adults, and occupational groups have been reported, but these have not yet been shown to be causal and the biological explanation tying the two remains unclear – it could lie in the mechanisms such as irritation, inflammation, immunosuppression, endocrine disruption, or a combination of these. So far, it is also unknown how pesticides interact with genes that increase susceptibility to asthma.This revies explores the relationship between pesticides and asthma. The present body of evidence is clearly insufficient to draw conclusions about the effect pesticide use has on asthma. It is uncertain whether pesticides cause asthma or act as triggers for asthma exacerbation or both.The main limitations of the current evidence are the outcome definition and the exposure assessment. With larger and preferably prospective studies and better asthma definition and exposure assessment, it will be easier to evaluate the association between individual pesticide exposure and asthma, and additionally it will be possible to identify gene–pesticide interactions. The identification and parameterization of these interactions will mean a big step forward in the understanding of the biological pathways that link pesticide exposure to asthma development and asthma exacerbation.[Amaral, A. 2014. Front Public Health.2:6]

The association of respiratory symptoms and indoor housing conditions among migrant farmworkers in eastern North Carolina.Farm labor housing has been described as among the worst in the nation, oftentimes with poor and unsanitary indoor living conditions. The objective of this study was to evaluate the association between indoor environmental risk factors and respiratory health among migrant farmworker occupants (N = 352) living in employer-provided housing. A cross-sectional sample of adult Latino male farm laborers were administered a questionnaire to identify the prevalence of major respiratory symptoms. Self-reported and independent observations were made to evaluate environmental respiratory risk factors and indoor housing conditions, including but not limited to, the presence of cockroaches, rodents, pesticides, and visible signs of mold. Spirometry was performed to evaluate lung function using FEV1 (forced expiratory volume in 1 second), FVC (forced vital capacity), and FEV1 /FVC ratio. Bivariate analysis was applied to evaluate associations between respiratory symptoms and selected indoor environmental risk factors. Findings for respiratory health included prevalence of wheeze (11.4%), coughing up phlegm (17.3%), tightness of chest (16.8%), and runny or stuffy nose (34.4%). Respiratory risks identified inside the dwellings included the use of pesticides or bug sprays for cockroaches (31.5%), rat or mouse poison (19.5%), visible signs of water damage in the bathroom (22.5%), and mold in the sleeping room (11.1%). Spirometry values were normal for most occupants, although statistically significant associations were found between mold and coughing up phlegm when not having a cold (P = .0262); presence of mold and asthma (P = .0084); pesticides used in the home and tightness of chest (P = .0001); and use of tobacco and coughing up phlegm (P = .0131). Although causal inference can be difficult to establish from a cross-sectional study, findings from this study represents suggestive evidence that indoor environmental risk factors may be contributory factors for respiratory health problems among this vulnerable workgroup population.[Kearney GD, Chatterjee AB, Talton J, et al. 2014. J Agromedicine. 19(4):395-405.]

Pesticide use, immunologic conditions, and risk of non-Hodgkin lymphoma in Canadian men in six provinces.Pesticide exposures and immune suppression have been independently associated with the risk of non-Hodgkin lymphoma (NHL), but their joint effect has not been well explored. Data from a case-control study of men from six Canadian provinces were used to evaluate the potential effect modification of asthma, allergies, or asthma and allergies and hay fever combined on NHL risk. Incident NHL cases (n = 513) diagnosed between 1991 and 1994 were recruited from provincial cancer registries and hospitalization records and compared to 1,506 controls. Subjects with asthma, allergies, or hay fever had non-significantly elevated risks of NHL associated with use of MCPA (OR = 2.67) compared to subjects without any of these conditions (OR = 0.81). Conversely, those with asthma, allergies, or hay fever who reported use of malathion had lower risks of NHL (OR = 1.25) versus subjects with none of these conditions (OR = 2.44). Similar effects were observed for asthma and allergies evaluated individually. Although there were some leads regarding effect modification by these immunologic conditions on the association between pesticide use and NHL, small numbers, measurement error and possible recall bias limit interpretation of these results.[Pahwa M, Harris SA, Hohenadel K, McLaughlin JR, et al.2012.Int J Cancer. 131(11):2650-9.]

Prenatal exposure to pesticide ingredient piperonyl butoxide and childhood cough in an urban cohort.A previous study from the authors reports that airborne concentrations of cis-permethrin, but not trans-permethrin, measured during pregnancy in an inner city pediatric cohort was associated with cough by age 5. However, the effect of subsequent exposures to both permethrins during early childhood, and to piperonyl butoxide (PBO, a synergist for residential pyrethroid insecticides) remains to be elucidated. This study hypothesized that prenatal and age 5-6 year measures of PBO and permethrins would be associated with cough at age 5-6 years in this cohort. Further, the authors explored the associations between these pesticide measures and wheeze, asthma, seroatopy, and fractional exhaled nitric oxide (FeNO).PBO and permethrins were measured in personal air during the third trimester of pregnancy and indoor residential air at age 5-6 years (n=224). Health outcome questionnaires were administered to the mothers of 5-6 year old children. Indoor allergen specific and total immunoglobulin (Ig) E production was measured from sera collected at age 5, and FeNO was measured at 5-6 years.Noninfectious cough was reported among 14% of children at age 5-6 years. Measures of prenatal PBO, but not age 5-6 year PBO or permethrins, increased the odds of cough. No significant associations were found for other measured health outcomes.Authors conclude prenatal PBO exposure was associated with childhood cough. It is unclear whether the observed effect is due mainly to PBO itself or residential pyrethroids of which PBO is an indicator.[Liu B, Jung KH, Horton MK, et al. 2012. Environ Int. 48:156-61.]

Gene-Environment Interactions and Airway Disease in ChildrenAsthma is the most common chronic disease of childhood in the United States, affecting nearly 6.5 million children. The prevalence and severity of childhood asthma have continued to increase over the past 2 decades, despite major advances in the recognition and treatment of this condition. Representing a heterogeneous collection of airway diseases, asthma has multiple pathologic processes resulting from the interactions of genetic susceptibility and environmental exposures. Preventing and treating airway disease in children will require new research approaches to understanding these complex interactions.[Schwartz, D. 2009. Pediatrics.123, Supplement 3:S151 -S159]

Rhinitis associated with pesticide exposure among commercial pesticide applicators in the Agricultural Health StudyTo investigate the association between current rhinitis and pesticide use, authors used data from 2245 Iowa commercial pesticide applicators in the Agricultural Health Study. 74% of commercial pesticide applicators reported at least one episode of rhinitis in the past year (current rhinitis). Five pesticides used in the past year were significantly positively associated with current rhinitis: the herbicides 2,4-D, glyphosate and petroleum oil, the insecticide diazinon and the fungicide benomyl. The association for 2,4-D and glyphosate was limited to individuals who used both in the past year (OR 1.42, 95% CI 1.14 to 1.77). Both petroleum oil and diazinon showed consistent evidence of an association with rhinitis, based on both current use and exposure–response models.[R E Slager, J A Poole, T D LeVan, et al. 2009. Occup Environ Med 2009 66: 718-724]

Pesticides and Atopic and Nonatopic Asthma among Farm Women in the Agricultural Health StudyStudying 25,814 farm women in the Agricultural Health Study, authors used self-reported history of doctor-diagnosed asthma with or without eczema and/or hay fever to create two case groups: patients with atopic asthma and those with nonatopic asthma. Growing up on a farm (61% of all farm women) was protective for atopic asthma and, to a lesser extent, for nonatopic asthma. Pesticide use was almost exclusively associated with atopic asthma. Any use of pesticides on the farm was associated only with atopic asthma. This association with pesticides was strongest among women who had grown up on a farm. Women who grew up on farms and did not apply pesticides had the lowest overall risk of atopic asthma compared with women who neither grew up on farms nor applied pesticides. A total of 7 of 16 insecticides, 2 of 11 herbicides, and 1 of 4 fungicides were significantly associated with atopic asthma; only permethrin use on crops was associated with nonatopic asthma.[Hoppin, J.et al. 2008. American Journal of Respiratory and Critical Care Medicine Vol 177. pp. 11-18]

Asthma's Impact on Children and AdolescentsLow-income populations, minorities, and children living in inner cities experience disproportionately high morbidity and mortality due to asthma.[Centers for Disease Control and Prevention, National Center for Environmental Health. 2005]

Summary health statistics for U.S. children: National Health Interview Survey, 2003.This report presents both age-adjusted and unadjusted statistics from the 2003 National Health Interview Survey (NHIS) on selected health measures for children under 18 years of age, classified by sex, age, race, Hispanic origin, family structure, parent's education, family income, poverty status, health insurance coverage, place of residence, region, and current health status. The topics covered are asthma, allergies, learning disability, Attention Deficit Hyperactivity Disorder (ADHD), use of prescription medication, respondent-assessed health status, school-loss days, usual place of health care, time since last contact with a health care professional, unmet dental needs, time since last dental contact, and selected measures of health care access. In 2003, most U.S. children under 18 years of age had excellent or very good health (83%). However, 10% of children had no health insurance coverage, and 5% of children had no usual place of health care. Thirteen percent of children had ever been diagnosed with asthma. An estimated 8% of children 3-17 years of age had a learning disability, and an estimated 6% of children had ADHD.[Centers for Disease Control and Prevention. 2005. Vital and Health Statistics 10 (223)]

Asthma and the environment: Connecting the dotsReport explores the rapid increase in asthma rates in recent years which cannot be explained by genetic causes alone, as genetic changes require many generations for population-wide effects to occur, and because asthma rates are increasing among people without a family history of asthma and allergies.[Solomon, G., EH Humphreys, and MD Miller. 2004. Contemporary Pediatrics 21: 73]

Asthma Prevalence and Control Characteristics by Race/Ethnicity - United States, 2002To assess asthma prevalence and asthma-control characteristics among racial/ethnic populations, CDC analyzed 2002 data from the Behavioral Risk Factor Surveillance System (BRFSS). This report summarizes the results of that analysis, which indicated that among the estimated 16 million (7.5%) U.S. adults with asthma, self-reported current asthma prevalence among racial/ethnic minority populations ranged from 3.1% to 14.5%, compared with 7.6% among whites.[Centers for Disease Control and Prevention. 2004. Morbidity and Mortality Weekly Report. 53(07);145-148]

Early-Life Environmental Risk Factors for Asthma: Findings from the Children's Health StudyTo investigate further whether the timing of such experiences and exposures is associated with the occurrence of asthma by 5 years of age, authors conducted a prevalence case-control study nested within the Children's Health Study, a population-based study of > 4,000 school-aged children in 12 southern California communities. Asthma diagnosis before 5 years of age was associated with exposures in the first year of life to wood or oil smoke, soot, or exhaust , cockroaches , herbicides, pesticides, and farm crops, farm dust, or farm animals. The ORs for herbicide, pesticide, farm animal, and crops were largest among children with early-onset persistent asthma. The risk of asthma decreased with an increasing number of siblings. Day care attendance within the first 4 months of life was positively associated with early-onset transient wheezing.[Salam, MT, YF Li, B Langholz, and FD Gilliland. 2004. Environmental Health Perspectives 112 (6): 760-765]

Health impacts of pesticide exposure in a cohort of outdoor workers.Study compared mortality of 1,999 outdoor staff working as part of an insecticide application program during 1935-1996 with that of 1,984 outdoor workers not occupationally exposed to insecticides, and with the Australian population. There was an increase in self-reported chronic illness and asthma, and lower neuropsychologic functioning scores among surviving exposed subjects when compared with controls.[Beard, J., et al. 2003. Environmental Health Perspectives 111(5):724-730]

Occupational asthma from fungicides fluazinam and chlorothalonil.Authors report two cases of occupational asthma caused by sensitisation to powdered fungicides fluazinam and chlorothalonil, from the same fungicide formulation plant. Both developed work related lower respiratory symptoms after a latent interval of asymptomatic exposure. The diagnosis in each case was confirmed with a serial peak flow record in the workplace followed by specific inhalation tests. These fungicides are known to cause dermatitis; this report indicates that these compounds can induce specific immunological reactions in the airways as well as skin.[Draper, A, P Cullinan, C Campbell, et al. 2003. Occup Environ Med 60: 76-77]

Respiratory symptoms in children and exposure to pesticidesA cross­sectional study was performed on children from a randomly selected sample of Lebanese public schools. Exposure to pesticides was evaluated by a standardised questionnaire and a residential exposure score, and respiratory symptoms were assessed. A chronic respiratory disease was reported in 407 (12.4%) out of 3,291 children. The baseline difference in mean age was small but statistically significant. Any exposure to pesticides, including residential, para­occupational and domestic, was associated with respiratory disease and chronic respiratory symptoms (chronic phlegm, chronic wheezing, ever wheezing), except for chronic cough.[Salameh, PR, I Baldi, P Brochard, et al. 2003. European Respiratory Journal 22: 507-512]

Asthma the Breathtaking DiseaseIn the last 20 years, asthma rates have soared to epidemic levels. Johns Hopkins Bloomberg School Of Public Health researchers investigate the food we eat, the air we breathe, and the way our bodies work for clues to better asthma treatment and prevention.[Field, M. 2002. The Magazine of Johns Hopkins Bloomberg School Of Public Health]

Chemical predictors of wheeze among farmer pesticide applicators in the Agricultural Health Study.Using the Agricultural Health Study, a large cohort of certified pesticide applicators in Iowa and North Carolina, authors explored the association between wheeze and pesticide use in the past year. Self-administered questionnaires contained items on 40 currently used pesticides and pesticide application practices. A total of 20,468 applicators, ranging in age from 16 to 88 years, provided complete information; 19% reported wheezing in the past year. The herbicides, atrazine and alachlor, but not 2,4-D, were associated with wheeze. Atrazine had a significant dose-response trend with participants applying atrazine more than 20 days/year.These associations, though small, suggest an independent role for specific pesticides in respiratory symptoms of farmers.[Hoppin, JA, DM Umbach, SJ London, et al. 2002. M J Respir Crit Care Med 165: 683-689]

Hazardous air pollutants and asthmaComplex mixtures (fine particulate matter and tobacco smoke) have been associated with respiratory symptoms and hospital admissions for asthma. Based on these observations and past experience with 188 hazardous air pollutants (HAPs), a list of 19 compounds that could have the highest impact on the induction or exacerbation of asthma was developed. Nine additional compounds were identified that might exacerbate asthma based on their irritancy, respirability, or ability to react with biological macromolecules. Recommendations for research are presented regarding exposure monitoring and evaluation of biologic mechanisms controlling how these substances induce and exacerbate asthma.[Leikauf, GD. 2002. Environmental Health Perspectives 110 (Suppl 4): 505-526]

Identifying and managing adverse environmental health effects: 4. Pesticides.Pesticide exposure can cause many different health effects, from acute problems such as dermatitis and asthma exacerbation to chronic problems such as chronic obstructive pulmonary disease and cancer. The resulting clinical presentations are undifferentiated, and specific knowledge of the links to environmental exposures is often required for effective diagnosis. In this article we illustrate the use of the CH2OPD2 mnemonic (Community, Home, Hobbies, Occupation, Personal habits, Drugs and Diet), a history-taking tool that assists physicians in quickly identifying possible environmental exposures. We also provide clinical information on the epidemiology, clinical presentations, treatment and prevention of pesticide exposures.[Sanborn, MD, D Cole, A Abelsohn, and E Weir. May 28 2002. CMAJ 166 (11): 1431-1436]

Fatal asthma in a child after use of an animal shampoo containing pyrethrinThis case suggests that physicians should also be alert to formulations marketed as pyrethrin.Pesticides of this class are being used with increasing frequency in homes and are easily available to the public. Manufacturers are not required by the Environmental Protection Agency to state on the label that the pyrethrum formulations are allergens. The possibility of an acute allergic reaction occurring from the use of any currently marketed pyrethrum insecticide should be considered in any case of respiratory or dermal allergy of unknown cause.[Wagner, SL. 2000. West J Med 173: 86-87]

Exposures of children to organophosphate pesticides and their potential adverse health effects.Research findings suggest that it is biologically plausible that organophosphate exposure may be related to respiratory disease in children through dysregulation of the autonomic nervous system. This Center for the Health Assessment of Mothers and Children of Salinas, or CHAMACOS in Monterey County, California, will assess (italic)in utero(/italic) and postnatal organophosphate pesticide exposure and the relationship of exposure to neurodevelopment, growth, and symptoms of respiratory illness in children.[Eskanazi, B, A Bradman, and R Castorina. 1999. Environmental Health Perspectives 107(Suppl 3): 409-419]

Is the increase in asthma prevalence occurring in children without a family history of atopy?Study investigated the familial associations of asthma and atopic disease in a population in which the prevalence of asthma and atopy is increasing. The prevalence of reported asthma (22.5%), eczema (24%) and hayfever (20%) in the children was high but similar to previous studies in this population. Asthma was reported in 20.8% of children of parents without a history of asthma and 18% of children of parents without any history of atopic disease. In children of parents without a family history of atopic disease suggests that much of the increase in asthma prevalence is occurring in children without a significant genetic predisposition. Childhood asthma developing in what would previously have been regarded as low risk families may differ in its aetiology from classical atopic asthma.[Christie GL, McDougall CM, Helms PJ. 1998. Is the increase in asthma prevalence occurring in children without a family history of atopy? Scott Med J. 43 (6): 180-182]

Five office workers inadvertently exposed to cypermethrinFive cases of poisoning by cypermethrin, a pyrethroid pesticide, are presented. The chemical was inadvertently introduced to the air-conditioning ducts and the patients inhaled it. Exposed patients experienced shortness of breath, nausea, headaches, and irritability. The exposure was compounded by repeated entry into the contaminated area and slow referral to a physician experienced in pesticide exposures.[Lessenger JE. 1992. J Toxicol Environ Health 35: 261-267]

Indoor spraying with the pyrethroid insecticide lambda-cyhalothrin: effects on spraymen and inhabitants of sprayed houses.In March 1990 a study was carried out in the village of Kicheba, United Republic of Tanzania, in which the pyrethroid insecticide lambda-cyhalothrin was sprayed on all the internal surfaces of houses and other shelters at a coverage of about 25 mg of active ingredient per m2. All the spraymen complained at least once of symptoms that were related to exposure to lambda-cyhalothrin, the commonest being itching and burning of the face, and nose or throat irritation frequently accompanied by sneezing or coughing. Facial symptoms occurred on non-protected areas only. The number of subjects affected and the duration of their facial symptoms were proportional to the amount of compound sprayed.[Moretto A. 1991.Bull WHO 69 (5): 591-594]

Asthmatic reactions to a commonly used aerosol insect killer.Seven patients with asthma and a history of chest tightness on exposure to aerosol insecticide sprays were studied. Under controlled conditions, objective measures of airways narrowing were taken before and after exposure to an aerosol insect killer (Mortein Pressure Pak). Chest tightness described as asthma was produced in all seven subjects, but only one showed a greater than 20% fall in FEV1, compared to baseline values. A further two subjects showed small changes in the maximum mid-expiratory flow rate. No changes were observed in the subjects' sensitivity to inhaled histamine before, and 24 hours after, exposure to the insecticide. Thus, exposure to a commonly used household insecticide spray produced marked symptoms in all subjects, but objective evidence of airways obstruction was present in only three, and no changes in bronchial reactivity to inhaled histamine occurred in any of the subjects[Newton JG and Breslin AB.1983. Med J Aust.1(8):378-80]

Occupational exposure to some synthetic pyrethroids (permethrin and fenvalerate).In a two-step study on exposure control method for occupational handling of permethrin was developed. Air sampling on a filter can be used in case of exposure to permethrin in powder form. The detection limit is 0.001 mg/m3. If biological sampling is used, the acid metabolite moiety in the urine must be monitored. However, the uptake after exposure to permethrin in forestry was too low, and no urine concentration could be found. The detection limit is 0.1 microgram/ml. Six persons in a plant nursery and six planters were studied in this way. Interviews were conducted with 139 planters. Irritative symptoms form the skin and upper respiratory tract were reported in 73% for fenvalerate, 63% for permethrin (trans/cis 75/25) and 33% for permethrin (trans/cis 60/40).[Kolmodin-Hedman, B, A Swensson, and M Akerblom. 1982. Arch Toxicol 50: 27-33]

Insecticides: household use and respiratory impairmentAn early study done in the 1960s in Hawaii shows that frequent household use of insecticides is correlated with an increased prevalence of respiratory disorders, including asthma and chronic bronchitis. The majority of the household pesticides used were insect sprays for mosquitoes, flies, and cockroaches[Weiner, BP, and RM Worth. 1969. Hawaii Medical Journal 28 (4): 283-285]